Green energy solution for beef processing plant

NH Foods Australia’s Oakey Beef Exports plant in Queensland is using anaerobic digestion technology to extract biogas from its organic wastewater streams. The beef processing plant on Queensland’s Darling Downs uses a Global Water & Energy (GWE) COHRAL (covered high-rate anaerobic lagoon) plant installed by Australian environmental engineer CST Wastewater Solutions and is striving to achieve total ROI in the foreseeable future.

“The wind doesn’t need to blow and the sun doesn’t need to shine to produce this green energy — it is a highly viable renewable in its own right, which complements the many excellent solar and wind energy sources suited to other projects. Ultimately, the plant will pay for itself with biogas then going on to produce virtually free energy for many years after that,” said Michael Bambridge, Managing Director of CST Wastewater Solutions.

A review of the NH Foods plant — which stores the biogas it produces in a 6000 m³ spherical polyester storage vessel — showed that the COHRAL plant reduced Oakey’s dependence on fossil fuel gas by the equivalent of upwards of AU$800,000 a year at current production levels of up to 4000 m³ of biogas a day. The plant also provides the capacity to produce more biogas in future, as stock throughput rises. The plant also increased the quality of the plant’s wastewater effluent by transforming waste extracted from it into easily stored energy.

The GWE anaerobic digestion technology involved in the installation is applicable to a range of industries with biological waste streams, including food and beverage applications and livestock processing operations. The plant occupies half the footprint of comparable covered anaerobic lagoons; the biogas it generates is used in the Oakey plant’s existing boiler, where it replaces natural gas, improving the beef processor’s cost efficiencies.

The GWE COHRAL plant. Image credit: CST Wastewater Solutions.

The Oakey Beef Exports plant exports its products to over 34 countries worldwide and is working towards a beef industry zero carbon footprint nationally by 2030. The United Nations Framework Convention on Climate Change recognises that beef is a major greenhouse gas (GHG) emitter with the beef sector of the livestock industry estimated to produce about 14% of all GHG emissions. Companies like NH Foods Australia are striving to ensure long-term sustainability and environmental benefit. In addition to reducing greenhouse gases by using natural gas as an energy source, Oakey Beef Exports’ plant is improving wastewater quality by removing more than 75% of organic content (chemical oxygen demand, COD) from effluent. The pre-treatment prior to the COHRAL system leads to better recoveries of valuable protein and fats, which would otherwise end up in the wastewater. This increases reliability by isolating clogging waste from the wastewater treatment plant.

The garden-like operating area in front of the wastewater treatment plant. Image credit: CST Wastewater Solutions.

“Energy costs are only going to go one way. The more efficient we can make this the better off we are,” Bambridge said.

The technology will be featured at this year’s Ozwater in Adelaide from 5–7 May 2020.